Testing apparatus

ABSTRACT

A unit for retaining a disposable electrophoresis test kit adapted for detecting the presence of hepatitis associated antigen and the like includes a base, means for illuminating said test kit spaced within said base, a work platform for supporting the test kit, wherein the platform has at least one pair of electrodes oppositely disposed thereon and connected to said base for generating an electric potential across said test kit; a removable cover connected to said base for enclosing said unit, said cover having a transparent viewing port spaced therein for observing said test kit and an electrical circuit in said unit for supplying power to said illuminating means and said electrodes.

United States Patent [19] Parent et al.

[ TESTING APPARATUS [75] Inventors: Ronald A. Parent, Columbia; John H.P. Andrews, Jr., Baltimore, both of Md.

[73] Assignee: Becton, Dickinson and Company,

East Rutherford, NJ.

[22] Filed: Mar. 9, 1972 [2]] Appl. No.: 233,079

[52] US. Cl 204/299, 204/180 G {51] Int. Cl B0lk 5/00 [58] Field ofSearch 204/180 G, 299

[56] References Cited UNITED STATES PATENTS 3,432,414 3/l969 Rand204/l80 G 3,616,456 lO/l97l Valmet t 204/299 3,635,808 l/1972 Elevitch204/180 G 3,674,678 7/1972 Post et a1. 204/299 3,677,930 7/1972 Meshbaneet a1 204/180 G X OTHER PUBLICATIONS Shandon Instruments, Tombs et al.,Acrylamide Gel 1 June 25, 1974 Electrophoresis, Jan. 1967, pp. 9 and 10.

Primary Examiner-John H. Mack Assistant ExaminerA. C. Prescott Attorney,Agent, or Firm-Kane, Dalsimer, Kane, Sullivan and Kurucz 5 7] ABSTRACT Aunit for retaining a disposable electrophoresis test kit adapted fordetecting the presence of hepatitis associated antigen and the likeincludes a base, means for illuminating said test kit spaced within saidbase, a work platform for supporting the test kit, wherein the platformhas at least one pair of electrodes oppositely disposed thereon andconnected to said base for generating an electric potential across saidtest kit; a removable cover connected to said base for enclosing saidunit, said cover having a transparent viewing port spaced therein forobserving said test kit and an electrical circuit in said unit forsupplying power to said illuminating means and said electrodes.

5 Claims, 13 Drawing Figures PATENTEU M2519" sum 05 W10 .IIIIIIIIIIIIPAIENIED .muzsmm sum 07 or 10 PATENIED JUN 2 51974 sum as ur m PATENTEDsum 09 or 10 F/G/Z PATENTEB JUN 2 51974 SHEET 10 0F 10 WRWRNu TESTINGAPPARATUS BACKGROUND OF THE INVENTION The invention relates to a systemfor detecting the presence of hepatitis associated antigen and otherimmunological procedures and, in particular, it relates to a compactpower supply and viewing test unit employed with a disposable test kitfor screening multiple blood or serum samples for hepatitis associatedantigen.

Electrophoresis has now become a well-established biochemical method foranalyzing complex biological substances and has acquired scientificapproval for use in clinical laboratory analyses in the study of normaland abnormal soluble and/or insoluble, animal and plant fluidconstituents, particularly as they relate to the diagnosis and treatmentof disease. In spite of the acceptance of this method as a biochemicalmethod of analysis and protection its use has been restricted by thecomplexities of interpreting the electrophoretic patterns and by thelimitations arising from the apparatus available in accomplishing thismethod. Conventional electrophoretic separation units and test systemsare illustrated in U.S. Pat. Nos. 3,407,133; 3,432,414; 3,479,265 andapplication Ser. No. 300,34l now U.S. Pat. No. 3,788,210, referred to inthe U.S. Pat. No. 3,479,265.

Consequently, effective use of the electrophoretic method has primarilybeen restricted to experts trained in interpreting and overcoming thecomplexities referred to hereinabove. The use of involved and intricateapparatus has resulted in many deficiencies. Such deficiencies include:inaccuracies arising from the application of dyes, such as fluorescentlabels to render the separated portions visible and the necessity forintricate optical scanning means or radio isotopic scanning means andthe like. The problem is particularly acute in the case of blood bankswhich are faced with a problem of screening hundreds of donors for viralor bacterial diseases employing relatively untrained personnel andsometimes under difficult field conditions. No practical system forscreening potential blood donors has been developed up to now which isadapted to be used with relatively untrained personnel. With theprevalance of hepatitis in modern society, the need to develop such amass detection system has become acute.

It is, therefore, a primary object of the present invention to provide asystem for rapidly testing and detecting multiple samples of blood forthe presence of a particular bacteria or virus antigen.

It is another object of the present invention to provide a unit forgenerating an electrical potential across a disposable electrophoresistest kit and for illuminating the kit within the unit to observe testresults.

It is yet another object to provide a screening apparatus for detectinghepatitis-associated antigen in blood plasma or serum adapted forrepeated use with high reproducibility and accuracy.

Other objects and advantages will become apparent from the followingdiscussion:

SUMMARY OF THE INVENTION These and other objects are met in a unit forretaining a disposable electrophoresis test kit adapted to detect thepresence of hepatitis associated antigen or the like which includes abase; means for illuminating said test kit spaced within said base; awork platform for supporting said test kit, said platform having atleast one pair of electrodes oppositely disposed thereon and connectedto said base for generating an electrical po tential across said testkit; a removable cover connected to said base for enclosing said unit,said cover having a transparent viewing port for observing said test kitand an electrical circuit in said unit for supplying power to saidilluminating means and said electrodes.

A disposable test kit adapted for use with the aforesaid unit includes abuffer tray hving a pair of spaced apart reservoirs for retaining anelectrophoresis buffer solution and a recessed platform spaced betweenthe reservoirs for retaining a gel coated test plate. The test plate hasa plurality of pairs of spaced apart test wells, and at opposite endsthereof, an unfoldable wick having one end thereof embedded in said gelfor electrically connecting the test plate with the buffer solution insaid tray reservoir.

It has been found that when a blood specimen containing hepatitisassociated antigen is placed in one test well on the test plate andsecond well of the test pair is filled with hepatitis associatedantibody, then upon electrophoresis of the test plate in the unit of theinvention, a visible precipitin line forms between the well pairs,thereby indicating the presence of hepatitis associated antigen. Theline may be visible to the naked eye on close examination, but isrendered completely visible by the use of illuminating means, such asfluorescent lights and the like. The unit is adapted to readily testover 50 individual blood specimens for bacteria or virus associatedantigen and, particularly, hepatitis associated antigen, also known asAustralia antigen. No dyes are employed, no intricate optical scanningmeans are employed and relatively unsophisticated technicians can easilyemploy the test unit of the invention in blood banks with highlyreproducible results.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustratean embodiment of the invention in which:

FIG. 1 is a fragmentary enlarged top plan view showing the formation ofa precipitin line on a disposable test plate of the invention;

FIG. 2 is a fragmentary, enlarged vertical sectional view of the testplate taken along line 2-2 of FIG. 1;

FIG. 3 is a top plan view of the test plate with a pair of wicksextending therefrom;

FIG. 4 is a perspective view of an alternate test plate;

FIG. 5 is a perspective view of a disposable test kit which may beemployed with the power and illumination unit of the invention;

FIG. 6 is an exploded view of the power and illumination unit;

FIG. 7 is a top plan view of the power and illumination unit containinga pair of test plates;

FIG. 8 is a top plan view of the unit in FIG. 7 with the cover removed;

FIG. 9 is a vertical cross-sectional view of the power and illuminationunit containing an electrophoresis test kit taken along line 99 of FIG.8;

FIG. 10 is a vertical cross-sectional view taken along line 10-10 ofFIG. 8;

FIG. 11 is a horizontal cross-sectional view taken along line 11-11 ofFIG. 9;

FIG. 12 is a functional block diagram of the electrica circuitry of thepower and illumination unit; and

FIG. 13 is a wiring diagram of the various circuits for the power andillumination unit.

DESCRIPTION OF PREFERRED EMBODIMENTS Turning now to FIGS. 6 and 10 thereis illustrated a power and illumination unit for housing a disposableelectrophoresis test kit. The unit 11 includes base 10. Base 10 ispreferably a rectilinear bin with an inlet orifice 12 for receivingpower cord 14. A second orifice 13 is spaced above power cord orifice l2and is adapted to receive a line fuse 16. A first and second pair ofthreaded studs 18 project upwardly from top flange 20 of base 10.

Base 10 has a plurality of slots 22 in its floor 24 in order to permitcirculation of air through the base to prevent overheating of the unitduring operation of the electrical components and lamps. To support thebase of supporting leg 19 is located adjacent each corner of the baseunderside.

As seen in FIGS. 6, 9, l and 11, chassis 26 is mounted to the floor 24of base by means of floor mounting screws 28 extending through the floor30 of chassis 26. As shown in FIG. 10, the screws also extend throughshoulders 32 of base floor 24 and are removably mounted thereto by meansof nuts 33.

Chassis 26 contains the illuminating and power elements for unit 11housing the disposable test kit. For this purpose chassis 26 has a pairof integral, upstanding walls 34 connected to opposite sides of thechassis floor 30 and terminating in a pair of opposed flanges 36extending toward each other in parallel relationship with chassis floor30.

As seen in FIGS. 9 and 10 a fluorescent lamp 38 is mounted along therespective side edges of the chassis co-extensive with each of saidflanges 36. At either end of each fluorescent lamp is a lamp socket 39.Each socket is mounted to the floor of said chassis 30.

In order to control the direction and intensity of light emitted by eachof the fluorescent lamps 38, a light diffuser 40 is mounted adjacenteach fluorescent lamp. As seen in FIGS. 9 and 11, each diffuser has avertical wall portion 42 which is co-extensive in length with the spacedadjacent to each fluorescent lamp. The height of wall 42 is less thanthe diameter of the fluorescent lamp. The wall serves to block thepassage of light emanating from the lamp in a horizontal directionacross the unit and upwardly to about a 20 arc. An angular flange 43extends downwardly from lamp diffuser wall 42 and serves to reflect anydiffused light to a central upper portion of the unit. Flanges 36prevent rear light passage.

Turning now to FIGS. 6 and 9 there are illustrated a pair of highvoltage warning lights 46 which cooperate with a cover actuatedv safetyinterlock system to remind the operator that electric circuits areactive immediately below the cover when the unit is in operation. Theelectrical connections between the high voltage lamps 46 and the safetyinterlock system is described hereinafter. High voltage warning lamps 46are set in sockets 44. Each socket is connected by mounting bracket 50to chassis wall 34.

As illustrated in FIGS. 6 and 840 working platform 52 is co-extensivewith the base of the unit and covers chassis 26. The working platformserves to support the disposable test plate apparatus and electrodes andalso houses the electrical components for initiating and monitoring theelectrophoresis testing. Platform 52 is preferably formed from a singlepiece of transparent acrylic plastic, suitably vacuum formed. Theworking platform includes a peripheral mounting shoulder portion 54co-extensive with top flange 20 of base 10. The rear portion 56 ofshoulder 54 contains the controls which operate the viewing and testingapparatus.

Adjacent the side shoulders 58 of the working platform are a pair ofspaced apart banana jacks 60 for receiving electrode pairs 62 of theelectrophoresis test kit.

As shown in FIG. 9 the central stage 64 of the work platform is steppedbelow the side and front shoulders 54, 58. The central stage of theunitary work platform contains a pair of opposed rectangular elongatedtroughs 66 extending from the front to the back of the central stage. Agenerally rectangular central plateau 68 extends between the opposedtroughs.

As illustrated in FIGS. 8 and 10, a pair of conventional reed safetyinterlocks 70 are connected, respectively, immediately beneath the frontand rear shoulders of the work platform. The safety interlocks areadapted to cooperate with a pair of magnets located in the unit cover toinsure that the unit is in the off position when the cover is removedfrom the unit.

At least one pair of removable electrodes 62 are provided for the unit.Each electrode has a banana plug 72 at one end adapted to fit into abanana jack 60 in the work platform. The body 73 of the electrode is inthe shape of an inverted U terminating at the other end in an elongatedmetallic probe 74 adapted to penetrate trough 66 near its bottom.

It is preferred that central stage 64 be transparent in order to permitlight from the fluorescent lamps to pass through the stage andilluminate an electrophoresis testing apparatus mounted on the stage.The cones of light emitted from the fluorescent lamps 38 are directed bythe diffuser 40 to intersect immediately below work platform centralplateau 68 and form a reinforced beam extending upwardly and outwardlytherefrom in a cone shaped configuration so as to provide maximumillumination to the central plateau.

Turning now to FIG. 7, removable unit cover 76 is formed from a unitarypiece of chemically resistant acrylic plastic. The portion that coversthe central stage 64 is shaped in such a manner that condensate whichforms from the underside of the cover during a test will not drip ontothe counterelectrophoresis plates. Four holes 78 penetrate the cover topermit the guide studs 18 protruding from base 10 to capture the cover.Four cap nuts lock the cover to the work platform and base to form acompletely aligned unit.

A pair of magnets 80 are embedded in the cover and are adapted tointeract with the high voltage interlock switches 70 to complete thepower circuit for the unit. As illustrated in the functional blockdiagram in FIG. 12 and the circuit diagram in FIG. 13 the reed interlockswitches form a part of the power control circuit and, if not properlyclosed by the magnets in the unit cover 76, the unit is not energized.This prevents an operator from suffering accidental electric shocksshould he insert his fingers into the unit during testing with the coverremoved.

As seen in FIGS. 6, 7, 9 and 10 cover 76 has a mounting rim portion 82which is generally co-extensive with the front, side and rear shoulderportion of working platform 52. Along each side edge 84 of the cover isa lifting wing 86 to permit an operator to remove the cover. Centralstage 54 of work platform 52 is enclosed by a generally rectangularraised portion 88 of cover 76. The vertical walls 90 of raised portion88 extend above work platform 52 sufficiently to clear electrodes 62.

To provide a surface which will direct condensate from the centralportion of the cover to the trough section 66 of the work areas a peakedroof or hip roof 92 is provided on the cover generally co-extensive withthe work area central plateau 68 and extending, on each side, above thetrough 66 of the work platform. In order to permit an operator to viewcentral plateau 68, which carries an electrophoresis test plate duringoperation, it is necessary that the peaked roof 92 be transparent. Asshown in FIG. 7 it is also preferable that a pair of opposed squares 94on the raised portion 88 of the cover be transparent. The squares arealigned above warning lamps 46.

While adapted for various testing purposes the aforedescribed apparatusis preferably employed in combination with a disposable electrophoresistest kit. While such kits have been proposed heretofore, as in US. Pat.No. 3,407,] 33, the following kit is preferred. The test kit includes arigid, preferably plastic buffer tray 96 as illustrated in FIGS. 5 and9. Buffer tray 96 includes a pair of opposed elongated buffer reservoirs98 spaced apart by a central recessed depression 100. Tray reservoirs 98are adapted to be received within work platform troughs 66. Depression100 rests on platform central plateau 68.

As shown in FIGS. 3-5, the power unit and viewer 11 is adapted toreceive and test one or two buffer trays. A disposable test plate 102 ofcomplimentary configuration with depression 100 of tray 96 is preferablyprovided with a precast layer of conventional agarose gel adapted forelectrophoresis work. The bottom of the plate is covered with a thinlayer of agarose gel and a plurality of opposed pairs of test wells 104are precut into the gel. Alternatively, the opposed pairs of test wells104 can be precut into the test plate which is then covered with a thinlayer of agarose gel. Each row 105 of opposed test wells is in parallelalignment, in use with buffer tray reservoirs 98.

Each test plate is equipped with an opposed pair of electrophoresis testwicks 106. A side edge 108 of each wick is embedded within the agarosegel. Prior to use each wick is tightly rolled for storage purposes. Eachwick is sufficiently long to extend, when unfolded, substantially to thebottom of each tray reservoir 98, as shown in FIG. 9.

Included with the electrophoresis test kit are premeasured quantities ofhepatitis associated antibody 110 and hepatitis associated antigen 112.A supply of premeasured solid buffer 111 is provided. The preferredbuffer is a mixture of sodium barbital, diethylbarbituric acid andthimerosal (125,000). In order to deposit the antigen and antibody intoa pair of opposed test wells of the test plate an automatic pipette 113with a disposable tip is provided. The preferred automatic pipette inthe HEPASCREEN Automatic Pipette distributed by SPECTRA BIOLOGICALS, adivision of Becton, Dickinson and Company.

Turning now to FIGS. 12 and 13 the counterelectrophoresis power unit andviewer 11 includes a power control circuit A. The power control circuitprotects the power and viewer unit against line surges on the inputpower and internal circuit overloads, controls the application of powerto the viewing lamps and power supply circuits, provides forinterruption of the power to the power supply circuit B when the topcover 76 is removed from the unit and indicates when power is beingapplied to the power supply circuit. The viewing lamps circuit Cprovides illumination for viewing the counterelectrophoresis test plates102 and interpreting the test results. The viewing lamps circuitconsists of two parallel connected conventional fluorescent lampcircuits electrically connected to lamp switch 126.

The power supply circuit B converts the AC input' power to filtered,regulated 180 volts DC power for electrophoresis testing using suitablerectifiers. It also isolates this input power from the output to lessenthe danger of electrical shock. The power supply positive output isconnected to the positive electrode 61. The negative output is connectedthrough the low current alarm circuits to the negative electrodes 63.

Each position on the work platform adapted to engage a disposable buffertray has a separate low current alarm circuit D. The circuit monitorsthe current from the power supply B through the test plate 102. If thecurrent is low (below about 16 micro amps) the low current alarm lamp114 (as illustrated in FIG. 8) associated with the tray position beingmonitored, will flash.

As shown in FIG. 12 the electrodes, both positive and negative, providethe electrical conduit for conducting current from the supply outputthrough the buffer solution, wicks, and counterelectrophoresis testplate 102.

FIG. 13 shows the circuit diagram for the electrical components of theunit and the general location for the electrical components. The powercontrol circuit includes line fuse 16 to protect against input poweroverloads and circuit overloads. Test power switch 120 controls powerapplication to caution lamps 46 and power supply circuits. Reed switchesinterrupt power to circuit B when cover 76 is removed. Power controlcircuit A also includes lamps 46 to indicate power is being supplied tocircuit B.

In order to operate the unit the solid buffer 111 is solubilized inwater and the resulting solution is dispensed to the opposed reservoirs98 of the buffer tray. Next, the cover is removed from the power andviewing unit by disengaging the cap nuts 79. The positive and negativeelectrodes 61, 63 are removed from the unit by pulling straight up onthe electrode body 62.

Next, the disposable buffer tray 9615 installed in the troughs 66 of thework platform. The positive and negative electrodes are then insertedinto their respective jacks in the unit.

Wicks 106 for the positive and negative electrode, as seen in FIG. 3,are unfolded from test plate 102. About 0.02 milliliters of hepatitisassociated antibody is pipetted using the automatic pipette into theleft hand well 116 of each pair of test wells as shown in FIG. 1. Nextabout 002 milliliters of control hepatitis associated antigen ispipetted into the right hand well 118 of the control pair. Finally about0.02 milliliter of test samples are pipetted into the right wells 118 ofeach test pair. A

7 separate pipette tip is employed for dispensing each test sample.

Next, test plate 102 is placed in the central depression 100 of buffertray 96. The keyed wick labeled positive electrode is immersed in thebuffer tray adjacent the positive electrode 61. For test purposes it isnecessary that the hepatitis associated antibody be placed in the testwell of the pair closest to the positive electrode. The test sample isplaced in the well closest to the negative electrode 63.

The other wick labeled negative electrode is then immersed in the trayadjacent the negative electrode 63. The cover is replaced on the powerand viewing unit and the unit is now ready for testing. The unit isenergized by closing the test power switch 120. Closing the switchenergizes the power control circuit and the warning lamps 46.

In order to confirm that sufficient current is passing through thecircuit formed by the positive and negative electrodes the respectivebuffer solutions in the buffer troughs, the wicks and test plate,indicator lamp 114 is provided for each testing portion. For testing thetray switch 124 is moved to the closed position thereby completing thetesting circuit. During testing the unit is preferably at roomtemperature to achieve optimum reaction conditions. The unit is operatedfor about 2 hours of continuous testing.

In order to read the unit and determine whether the specified samplecontained hepatitis associated antigen, lamp switch 126 is closedcompleting the circuit through the fluorescent lamps 38. Stronglypositive test samples will form distinctive illuminated precipitin lineswithin 30 minutes. The full 2 hour test period is employed to insure thedetection of extremely low titered hepatitis associated antigenpositives.

Prior to illuminating the test plate after the testing period iscompleted, all switches are turned to the off or opened position. Thecover is'removed from the power and testing unit 11. The viewer powerswitch 126 is then closed thereby actuating the fluorescent lamps. Thetest plate is examined for precipitin lines. A typical precipitin lineis illustrated in FIG. 1. For. comparision purposes a precipitin lineshould appear between the control antigen and antibody, indicating thatthe system has functioned properly.

Upon completion of test plate evaluation the viewing switch 126 isopened and the buffer tray and test plate are removed from the unit andpreferably autoclaved.

Generally, impact resistant rigid materials are employed for the unit.The cover, base and work area are preferably formed from chemicallyresistant, high impact KYDEX brand acrylic plastic. The disposablebuffer tray is preferably formed from clear polyvinyl chloride. In orderto provide a bench mark on the buffer trays to indicate that the properamount of buffer solution is present in each, a molded step (not shown)may be formed at the inner top edge of each buffer tray reservoir at theappropriate level.

As indicated in FIG. 11 baffle 37 is employed to separate heat sensitiveelectrical components mounted on the chassis from the fluorescent lamps.Chassis 26 is preferably formed from aluminum. Electrodes 62 arepreferably formed from LEXAN brand polycarbonate plastic.

The unit has been licensed by the Division of Biologics Standards forhepatitis associated antibody. The following theory of operation hasbeen postulated. The agarose gel formation causes the antigen moleculein the test wells to become negatively charged and the antibodymolecules to be nearly neutral. An electric field is established acrossthe plate between the wicks when the plate is placed in the test unitand the test power activated. The resulting electrophoretic forceaccelerates the movement of the negatively charged antigen molecules andthey converge with the antibody molecules in less time then if actedupon by only a diffusive force. The nearly neutral antibody molecule ismoved toward the antigen by electro-osmosis.

Additionally, the electrophoretic force causes migration of hydrogenions. The buffer solution acts as a reservoir of hydrogen ions tomaintain the pH in the agarose gel so that the antigen remains chargedthroughout the test. The charge on the antigen, a macromolecule, isinfluenced by the concentration of hydrogen ions.

During testing the electrical resistance inherent in the agarose gelcauses the gel to heat and limits the voltage difference that can beapplied across the test plate. In the illustrated unit the voltagedifference across the plate is about 25 volts. The test plate is about7.5 centimeters wide. Monitoring the current across the test plateprovides verification that the correct voltage difference is beingapplied across the plate. The low current indicator lights signal whenthe current drops below that needed to provide satisfactory testresults.

Among the advantages provided by the counterelectrophoresis power andviewer unit are the peaked cover or hip rooftype cover which provides acontrolled environment for optimum reaction conditions and preventscondensed liquid (heated by the fluorescent lamps or the like) fromdripping onto the test plates. The cover actuated safety interlockswitches interrupt the voltage when the cover is removed thus protectingthe user from accidental contact with high voltage. The built-in viewinglamps provide light at proper angle and intensity for interpreting testresults. The infection risk to laboratory personnel is minimized byeliminating the need for handling the test plates to view the testresults. Further, a second test plate can be added even while a firsttest is being run without effecting results. The disposable test kitincluding the buffer tray and test plate with prefolded wicks eliminatescontamination problems.

A workable electrophoresis unit is 14 inches wide by 17 inches long by 5inches high. It will be obvious to those skilled in the art that variousmodifications may be made the specific embodiments described herein.While particular embodiments have been discussed it will be understoodthat the invention is not limited thereto and that it is contemplated tocover any such modifications in the appended claims as fall within thetrue spirit and scope of the invention.

Wherefor we claim:

1. Unit for retaining a disposable electrophoresis test kit adapted todetect the presence of hepatitis associated antigen or the likecomprising:

a. a base;

b. means for illuminating said test kit spaced within said base;

0. a work platform for supporting said test kit, said platform having atleast one pair of electrodes oppositely disposed thereon and connectedto said base for generating an electrical potential across said testkit;

d. a removable cover connected to said base for enclosing said 'unit,said cover having a transparent viewing port for observing said testkit;

e. an electrical circuit in said unit for supplying power to saidilluminating means and said electrodes;

f. said work platform having a spaced apart elongated troughs inparallel relation and said cover has a hip roof portion substantiallyenclosing said troughs; and

g. said means for illuminating said test kit including a pair of opposedlights mounted beneath said work platform and means for interceptingpredetermined portions of light emitted from said lights such that thespace between said troughs is highlighted to facilitate visual receptionthereof.

2. The invention in accordance with claim 1 including at least onesafety interlock switch for opening and closing said electrical circuitand one magnet for each said interlock switch mounted in said cover foractuating said switch and closing said electrical circuit, saidinterlock switch being normally opened.

3. The invention in accordance with claim 1 in combination with adisposable test kit, said kit including a buffer tray having a pair ofspaced apart reservoirs, each reservoir adapted to seat in one of saidopposed troughs, a recessed platform spaced between said reservoirs andan agarose gel coated test plate having a plurality of pairs of spacedapart test wells and, at opposite ends of said plate, an unfoldable wickhaving one end thereof embedded in said gel wherein said test plate isreceived in said recessed platform on said buffer tray.

4. A unit for retaining a disposable electrophoresis test kit adapted todetect the presence of hepatitis associated antigen or the likecomprising:

gated rectangular troughs, each trough spaced above one of saidfluorescent lamps;

e. at least one pair of electrodes removably mounted on said platform,one of said electrodes associated with each trough and extendingsubstantially to the bottom of said trough;

f. at least one magnetically actuated interlock switch mounted on saidplatform;

g. a removable cover for said work platform, said cover having atransparent hip roof portion spaced above said troughs and one magnetconnected to said cover for each said interlock switch adapted to closesaid interlock switch upon engagement;

h. an electrical circuit in said unit for supplying power to saidilluminating means and electrodes, wherein each said interlock switchelectrically connected to said circuit and is adapted to open saidcircuit when in the normally open position and to close said circuitwhen actuated by said magnet; and

i. a circuit electrically connected to each of said electrodes formonitoring the current passing through said electrodes and for signalingwhen said current falls below a predetermined level necessary forelectrophoresis.

5. Unit for retaining a disposable electrophoresis test kit adapted todetect the presence of hepatitis associated antigen or the likecomprising:

a. a base;

b. means for illuminating said test kit spaced within said base;

c. a work platform for supporting said test kit, said platform having atleast one pair of electrodes oppositely disposed thereon and connectedto said base for generating an electrical potential across said testkit;

d. a removable cover connected to said base for enclosing said unit,said cover having a transparent viewing port for observing said testkit;

e. an electrical circuit in said unit for supplying power to saidilluminating means and said electrodes; and

f. a circuit electrically connected to each of said electrodes formonitoring the current passing through said electrodes and for signalingwhen said current falls below a predetermined level necessary forelectrophoresis.

1. Unit for retaining a disposable electrophoresis test kit adapted todetect the presence of hepatitis associated antigen or the likecomprising: a. a base; b. means for illuminating said test kit spacedwithin said base; c. a work platform for supporting said test kit, saidplatform having at least one pair of electrodes oppositely disposedthereon and connected to said base for generating an electricalpotential across said test kit; d. a removable cover connected to saidbase for enclosing said unit, said cover having a transparent viewingport for observing said test kit; e. an electrical circuit in said unitfor supplying power to said illuminating means and said electrodes; f.said work platform having a spaced apart elongated troughs in parallelrelation and said cover has a hip roof portion substantially enclosingsaid troughs; and g. said means for illuminating said test kit includinga pair of opposed lights mounted beneath said work platform and meansfor intercepting predetermined portions of light emitted from saidlights such that the space between said troughs is highlighted tofacilitate visual reception thereof.
 2. The invention in accordance withclaim 1 including at least one safety interlock switch for opening andclosing said electrical circuit and one magnet for each said interlockswitch mounted in said cover for actuating said switch and closing saidelectrical circuit, said interlock switch being normally opened.
 3. Theinvention in accordance with claim 1 in combination with a disposabletest kit, said kit including a buffer tray having a pair of spaced apartreservoirs, each reservoir adapted to seat in one of said opposedtroughs, a recessed platform spaced between said reservoirs and anagarose gel coated test plate having a plurality of pairs of spacedapart test wells and, at opposite ends of said plate, an unfoldable wickhaving one end thereof embedded in said gel wherein said test plate isreceived in said recessed platform on said buffer tray.
 4. A unit forretaining a disposable electrophoresis test kit adapted to detect thepresence of hepatitis associated antigen or the like comprising: a. arectilinear bin having air vents therein; b. a chassis mounted withinsaid bin, said chassis having mounted thereon a pair of parallellyopposed fluorescent lamps; c. means for intercepting the light emittedfrom each said lamp to provide an illuminating arc of at least about 80*from the vertical directed upwardly toward the central portion of saidbin; d. a work platform mounted on said bin above said chassis, saidwork platform having a pair of elongated rectangular troughs, eachtrough spaced above one of said fluorescent lamps; e. at least one pairof electrodes removably mounted on said platform, one of said electrodesassociated with each trough and extending substantially to the bottom ofsaid trough; f. at least one magnetically actuated interlock switchmounted on said platform; g. a removable cover for said work platform,said cover having a transparent hip roof portion spaced above saidtroughs and one magnet connected to said cover for each said interlockswitch adapted to close said interlock switch upon engagement; h. anelectrical circuit in said unit for supplying power to said illuminatingmeans and electrodes, wherein each said interlock switch electricallyconnected to said circuit and is adapted to open said circuit when inthe normally open position and to close said circuit when actuated bysaid magnet; and i. a circuit electrically connected to each of saidelectrodes for monitoring the current passing through said electrodesand for signaling when said current falls below a predetermined levelnecessary for electrophoresis.
 5. Unit for retaining a disposableelectrophoresis test kit adapted to detect the presence of hepatitisassociated antigen or the like comprising: a. a base; b. means forilluminating said test kit spaced within said base; c. a work platformfor supporting said test kit, said platform having at least one pair ofelectrodes oppositely disposed thereon and connected to said base forgenerating an electrical potential across said test kit; d. a removablecover connected to said base for enclosing said unit, said cover havinga transparent viewing port for observing said test kit; e. an electricalcircuit in said unit for supplying power to said illuminating means andsaid electrodes; and f. a circuit electrically connected to each of saidelectrodes for monitoring the current passing through said electrodesand for signaling when said current falls below a predetermined levelnecessary for electrophoresis.